Feed control for shirring mechanism



Nov. 6, 1956 B. N. PIERCE 2,769,416

FEED CONTROL FOR SHIRRING MECHANISM Filed N v. 19, 1955 In wen 602: fierizardmPierc-e jfi-S' Attorney's States Patent i "Merrow' Machine Company, Hartford, Conn, a corporation of Connecticut Application November 19, 1953, Serial No. 393,203

7 11 Claims. (Cl. 112-209) This invention relates to sewing machine feeding mechanism for shirring or gathering material, and particularly concerns the control mechanism for varying the difference in the amount of feed effected by each feed dog to thereby determine the amount by which the material between the feeding devices is fulled."

In shirring or gathering mechanisms of the type to which this invention is applicable, front and rear feed dogs are moved in work feeding strokes of respectively difierent feeding effect so that certain material between the front and rear feed devices is fulled more or less according to the degree of differential effected by the strokesof the respective feeding devices. Such fulling of material may be applied to either one or more plies comprising the work advanced by the feeding devices to suitable stitching elements.

An arrangement for controlling the amount or degree to, which the fulling is efiected is disclosed in co-pending application Serial No. 301,426, filed'July 29, 1952, by Edward R. Larnoureux and Bernard N. Pierce for Feed Control for Shirring Mechanism. As disclosed in that application, the feed dogs are moved in orbital paths determined by positions of guide blocks which slidably support yokes formed on carriers for the feed dogs. The position of one of the guide blocks is adjusted by adjusting the position of its pivot through rotation of a rock shaft from which the pivot eccentrically extends. v

The object of thevpresentinvention is to provide an improved shirring feed control mechanism with operating parts of the mechanism enclosed within the mechanism compartment of the machine frame or the feeding mechanism compartment at the end of the frame. An .oth'er objectis to provide improved stops for limiting ;an gular displacement of a rock shaft to thereby establish .definite positions between which the orbit of movement .of a feed dog may be adjusted to vary the amount by which the material isfulled. Another object is to provide a further stop for limiting the extreme range of movement of the control mechanism. A

-In the attainment of these objects, one feature of the invention resides in the arrangement of a rock shaft with one end in the mechanism compartment of the machine frame, and the other end extending toward the carrier for the adjustable feed dog with a-collar thereon having a' stub-shaft forming a pivotal support for a guide'block on which ayoke on the carrier is slidable. A lever extendsradially from this collar to rotate the rock shaft and thereby adjust the position of the pivot for the guide block to change the position of the orbital path through which the feed dog is moved. Another feature of the invention resides in the provision in the mechanism compartmenton the one end of the rock shaft of a segmental stoplwithj adjustable abutments for engaging the ends of the stop to limit angular displacement of the rock Shaft. A further. stopin the form of an abutment engageable in a radial bore of the rock shaft limitsthe extreme range of rotation of the rock shaft.

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Other objects, advantages and features of the invention will become apparent from the following specification taken in conjunction with the accompanying drawings wherein:

Fig. 1 is an elevation of the left end of a Merrow curved needle, over-edge sewing machine with certain parts in section and others omitted or partly shown for purposes of clearness; and

Fig. 2 is a horizontal section taken substantially on the line 2-2 of Fig. 1.

As illustrated in the drawings, this Merrow sewing machine is provided at its head or left end with a bearing 11 for a lower or main shaft 12 and with a bearing 13 for an auxiliary or upper shaft 14. For rotating shafts 12 and 14 in unison, means (not shown) are housed within a mechanism compartment 15 formed within frame 16. A curved needle 17 is held in a carrier 18 pivotally supported by a stud 19 threaded into the machine frame. By means of a link connecting carrier 18 with upper shaft 14, the needle 17 is moved in an arcuate path to cooperate with conventional loopers (not shown) in the formation of over-edge chain stitching.

The feeding mechanism illustrated includes a front feed dog 21 and a rear feed dog 22, respectively secured to front and rear feed bars or carriers as 23 and 24. The relative action of feed dogs such as 21 and 22 required to produce shirred work is extensively exemplified in the prior art. A detailed description of the illustrated mechanism may be found in the aforementioned co-pending application of Edward R. Lamoureux and Bernard N. Pierce, entitled Feed Control for Shirring Mechanism, Serial No. 301,426, filed July 29, 1952. Briefly, feed dogs 21 and 22 are manipulated in orbital paths determined by the movements of carriers 23 and 24. Movement or manipulation of the carriers in orbital paths is effected by eccentrics, such as eccentric 25, on the end of lower'shaft 12. The positions of these orbital paths are determined by pivotally supported guide blocks 26 and 26 and 27 on which are respectively slidable yokes 28 and 29 at the rear of the carriers 23 and 24.

The present invention concerns an arrangement of parts for changing the position of a guide block 26 to thereby alter the position of the orbital path in which front feed dog 21 is moved so that the orbit of the feed dog 21, as determined by the carrier on which it is mounted, may be located in different positions to effect various results. l

A short rock shaft 31 is-rotatable in bearing bore 32 formed in the end wall 33 of the sewing machine, frame 16. Rock shaft 31 has its inner end disposed within the mechanism compartment 15 of the machine frame and its outer end extends toward front feed dog carrier 23, terminating adjacent carrier block 26.

Secured to the outer end of therock shaft 31 as by a screw 34 is a collar or hub 35 formed with a radially extending actuating lever 37. Exending axially from one face ofv the collar 35 is a pin or stub shaft 38 eccentrically arranged with respect to the axis of rock shaft 31 and'extending into bore 41 formed in the guide block 26 so the stub shaft-38 forms a pivotal support for the guideblock.

Angular displacement of the rock shaft 31 to vary the position of stub shaft 38 and thereby change the orbital path of feed dog carrier 23 may be effected by moving actuating lever 37 as by a treadle (not shown) vor other manually actuated device. To limit the angular displacement of rock shaft 31, a stop element 42 issecured to the inner end 31' of the rock shaft within the mechanism compartment 15. This stop element 42 is of segmental form having end surfaces 43 and 44 which are respectively engaged by abutments 45 and 46 on the ends of screws 47 and 48 which extend through the rear Wall of the p 2,769,416 7 a t machine. A' desirediadjustment of abutment 45 with respect tostop. surface 43 may be obtained by. turning screw 47, and for securing such adjustment against accidental displacement, a washer 51 and suitable lock nut 52 are provided. Similarly, screw 48 is eifective with respect to stop surface 44 and abutment. and is pro vided with awas'her 53 andlock nut 54. From the foregoing description it will be apparent that the limiting stops Tension spring 49, which is connected between element 50 on the stop member 42 and element 50 on the machine frame 16, normally urges the rock shaft 31 in a clockwise direction as viewed in Fig. 1 so stop surface 43 engages abutment 45 on the screw 47. Actuating lever 37 may be moved (as by a treadle, not shown) to rotate the rock shaft 31 and thereby change the location of the stub shaft 38 forming the pivot for theguide block 26 to change the position of the orbital path in'which the 'frontfeed dog 21 is moved by the front feed dog carrier 23. The limit of movement of the rock shaft'is determined by the position of abutment 46 for engaging stop surface 44 on the segmental stop 42. Usually, the two adjustable stops in the form of abutments 45 and 46 de termine two positions of the stub shaft 38 to provide two different degrees of differential feed for the feed dogs 21 'and 22. Thus, through manipulation of actuating lever 37, guide block 26 may be established in either of two positions at the will of the operator, such positions having been predetermined to give. the desired results by appropriate adjustmentof stop screws 47 and 48;

It is desirable that the extreme range of angular displacement of rock shaft 31 be so limited as to prevent stub shaft 38, carried by the collar 35 on the rock shaft, from being moved to positions which are impractical. For this purpose, another limiting stop in the form of screw 55 is threaded into machine frame 16 and has its beveled point 58disposed within a countersink 59 in the rock shaft 31. Thus, beveled point 58 forms an abutment for "controlling the extreme range of movement of the rock shaft 31 by engaging the sides of the countersink 59.

In addition to the convenient arrangement of the adjustable stops for controlling the limited range of angular j side the housing. 7

Having thus described the invention, what is claimed is: 1. In a sewing machine feedingmechanism having a guide block, a feed dog carrier formed witha yoke slidguide block, a feed dog carrier formed with a yoke slidable on said block, a feed dog. on said carrien andtneausgfor moving said carrier to move said feed dog in an orbital path the position of which is determined by the position 'of said guide block, a feed control comprising a rock shaft journaled in the frame ofthe machine, an eccentn'cstub shaft extending axiallyffrom one end of said rock V shaft and forming a pivotal support for said guide block,

w an actuating lever. extending radially from said: OIIEabIld ofsaid rock shaft for turning said rock shaft to shift said i stub shaft and thereby change the position of the"orbital?,

path in which said feed dog is moved, a stop'on the other end of said rock shaft, and adjustable abutments. on the:

frame of the machine for engagingsaid stop to limit the angular displacement of said rock shaft in both directions.

3. In a sewing machine feeding mechanism having a guide block, a feed dog carrier formed'with a yoke slidable on said block, a feed dog on said carrier,'and means for moving said carrier to move said feed dog in an orbital path the position of which is determined by the position of said guide block, a feed control comprising a rock shaft journaled in the frame ofthe machine, a collar on the end of said rock shaft, an eccentric stub shaftcxtend ing axially from said collar beyond said one end of said rock shaft and forming a pivotal support for said guide block, an actuating'lever'extending radially from said collar for turning said rock shaft to shift said stub shaft and thereby change the position of the orbital path which said'feed dog is moved, a segmental stop on the other end of said rock shaft, a pair of abutment on the frame of the machine for engaging the ends of said seg mental stop, .and means for adjusting said abutments'to variably limit the angular displacement of said rock shaft in both directions. V j Y 4. In a sewing machine feeding mechanism as defined in claim 2 wherein said rock shaft of the feedcontrol is provided with an additional. stop to limit the angular able on said block, a feed dog on said carrien and means for moving said carrier to move said feed dog in an orbital path, means for shifting the position of said orbital pathrelative to said frame comprising a rock shaft journaled in the'frarne of the machine, a collar on the end of said rock shaft, an eccentric stub shaft extending axially from said, collar beyond the end of said rock shaft and forming a pivotal support for said guide block, and an actuating lever extending radially from said collar for turning said rockshaftjto shift said stub shaft and thereby an l gs on. t l pa h i h ch a f e dqs sjmo 1 V a, sewing ma hinei dinsm ghani mg a inega displacement thereof irrespective of the positions ofsa'id.

adjustable abutments.

5. In a sewing machine feeding mechanism as defined angular displacement thereof irrespective of the positions of said adjustable abutments. V

6. In a sewing machine having a frame and ameclranism compartment in said frame, a feed mechanism m= prising a rock shaft having one end in said mechanism. compartment and the other end extending through the a machine frame, an eccentric stub shaft extending axially from said other end of said rock shaft, a guide block pivot ally supported on said stub shaft, a feed dog carrierjpro vided with a yoke slidable on said guide block, a feed dog on-said carrier, means extending from said mechantsni. compartment for moving said carrier to move said feed.

dog in an orbital path the position of which is determined by the position of said guide block, and means for turn-w vided with a yoke slidable on said guide block, a feed dog;

on said carrier, means extending from said mechanism compartment for movingsaid carrier to move said'feed dog in an orbital path the position of which isdetermined by the position of said guide block, a stop on said one end of said rock shaft in said mechanism compartmentfor limiting angular displacement of said rock shaftend,

means r ing; s id. r ck-sha to sh ftsa rl, stub,

and thereby change the position of the orbital path in which said feed dog is moved.

8. In a sewing machine having a frame and a mechanism compartment in said frame, a feed mechanism comprising a rock shaft having one end in said mechanism compartment and the other end extending through the machine, an eccentric stub shaft extending axially from said other end of said rock shaft, a guide block pivotally supported on said stub shaft, a feed dog carrier provided with a yoke slidable on said guide block, a feed dog on said carrier, means extending from said mechanism compartment for moving said carrier to move said feed dog in an orbital path the position of which is determined by the position of said guide block, a stop on said one end of said rock shaft within said mechanism compartment, adjustable abutments on said frame extending into said mechanism compartment for engaging said stop to limit angular displacement of said rock shaft in both directions, and means for turning said rock shaft to shift said stub shaft and thereby change the position of the orbital path in which said feed dog is moved.

9. In a sewing machine a feed mechanism as defined in claim wherein said stop is in the form of a segmental element on said one end of said rock shaft and said adjustable abutments engage the ends of said segmental element.

10. In a sewing machine having a frame and a mechanism compartment in said frame, a feed mechanism comprising a rock shaft having one end in said mechanism compartment and the other end extending through the machine frame, a collar upon said other end of said rock shaft, an eccentric stub shaft extending axially from said collar beyond said other end of said rock shaft, a guide block pivotally supported on said stub shaft, 3. feed dog carrier provided with a yoke slidable on said guide block, a feed dog on said carrier, means extending from said mechanism compartment for moving said carrier to move said feed dog in an orbital path the position of which is determined by the position of said guide block, limit stop means cooperating with said shaft for limiting the extreme range of angular displacement of said rock shaft, a control stop on said one end of said rock shaft within said mechanism compartment, adjustable abutments extending into said mechanism compartment for engaging said control stop to limit angular displacement of said rock shaft within said extreme range, and means for turning said rock shaft to shift said stub shaft and thereby change the position of the orbital path in which said feed dog is moved.

11. In a sewing machine having a frame and a mechanism compartment in said frame, a feed mechanism comprising a rock shaft having one end in said mechanism compartment and the other end extending through the machine frame, a collar upon said other end of said rock shaft, an eccentric stub shaft mounted in said collar and extending beyond said other end of said rock shaft, a guide block pivotally supported on said stub shaft, a feed dog carrier slidable on said guide block, a feed dog on said carrier, means extending from said mechanism compartment for moving said carrier to move said feed dog in an orbital path the position of which is determined by the position of said guide block, and an integral lever extending radially from said collar for turning said rock shaft to shift said stub shaft and thereby change the position of the orbital path in which said feed dog is moved.

References Cited in the file of this patent UNITED STATES PATENTS Re. 24,005 Knaus et al May 17, 1955 1,214,063 Onderdonk Ian. 30, 1917 1,565,665 Merrow Dec. 15, 1925 1,731,080 Motfatt Oct. 8, 1929 2,659,330 Knaus Nov. 17, 1953 2,711,144 Jullie June 21, 1955 

